A conventional power supply control device is disclosed in PTL 1, for example.
The power supply control device (electronic control device for a vehicle, as referred in PTL 1) disclosed in PTL 1 includes a main microcontroller, a sub microcontroller, a first power supply means for supplying voltage to actuate the main microcontroller, and a second power supply means for supplying voltage to actuate the sub microcontroller. The main microcontroller is started up when a prescribed startup condition is satisfied. The main microcontroller started up determines whether or not to actuate the sub microcontroller. Based on the result of the determination, supply of power from the second power supply means to the sub microcontroller is controlled.